This invention relates to the hub assembly of an impeller. Impellers are a component of an agitator assembly which is used to mix fluids. The impeller may be secured to the agitator shaft at various locations within a container or vessel. Multiple impellers may be mounted on a single shaft.
The impeller consists of a hub assembly, which secures the impeller to the agitator shaft, and a set of radial blades which extend outward from the hub assembly. The agitator shaft is driven rotationally, which moves the blades through the fluid, thus mixing the container contents.
In certain industries, the fluid contents of the container may come in contact with animals or humans. The equipment designed to produce such material must be sanitary or hygienic in design. The definition of such a design is that it must be cleanable, sterilizable and free of dead spaces or crevices.
Traditional adjustable impeller designs are not suitable for use in sterile equipment as they typically contain threads from screws or crevices which do not comply with hygienic design standards. Impeller hubs used in such sterile equipment are, therefore, typically welded to the shaft in order to seal all dead spaces. This does not allow the user the ability to change the location of the impeller assembly.